1. Field of the Invention
The present invention relates to image forming apparatuses.
2. Description of the Related Art
Conventionally, there has been an electrophotographic image forming apparatus as one example of an image forming apparatus. The electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) is configured to form an image on a recording medium using an electrophotographic image forming process. The image forming apparatus includes an electrophotographic copying machine and an electrophotographic printer (e.g., a light-emitting diode (LED) printer or a laser beam printer). In the image forming apparatus using an electrophotographic image forming process, a process cartridge system capable of attaching/detaching a cartridge to the image forming apparatus body is available, and the cartridge integrally includes an electrophotographic photosensitive member and process units acting on the electrophotographic photosensitive member. According to the process cartridge system, a user can perform maintenance of the apparatus by himself without relying on a serviceman. Therefore, operability of the image forming apparatus can be improved.
On the other hand, there is a difference between a consumption period of a developer and a life period of a processing means. Thus, some apparatuses separately include a process cartridge having a developing device and a toner cartridge for supplying a developer (hereinafter referred to as “toner”).
This toner cartridge is called a toner supplying type cartridge.
In this system, a toner is an ultra fine powder. Thus, in a toner supplying operation, the toner cartridge is put within the image forming apparatus body so that the toner is not scattered, and the toner is supplied in small quantities from a small supplying outlet in the toner cartridge to the process cartridge.
When such a toner cartridge is left and stored under a vibration in the course of a physical distribution or at high temperature and high humidity for a long period of time, toner clumps together so that a toner may be solidified (that is, a toner bridge) in a container body. As a consequence, if the clumped toner having low fluidity is supplied to a small opening part, the opening part may be clogged with the toner (that is, a packing may occur). In such a case, the toner is not discharged from the opening part so that a shortage of the toner appears near a developing roller in a developing container, and thus a normal image may not be obtained.
Therefore, it is necessary to constantly discharge a predetermined amount of the toner by using a method for breaking the toner bridge so as to keep uniform fluidity.
Japanese Patent Application Laid-Open No. 10-63082 discusses a method in which a projection part formed on an inner wall of a conveying member comes to contact with the toner conveying member constituted by an elastic body that is driven to apply vibration to the conveying member.
However, when the vibration is applied while conveying a toner, the clumped toner is forwarded before the toner is broken, and thus a packing may become worse.